Multiphase controller communication

Abstract

A multiphase controller includes an integrator enable terminal, a pulse width modulator, an error integrator, an open drain driver, and an integrator enable circuit. The integrator enable terminal is adapted to be coupled to the integrator enable terminal of a different instance of the multiphase controller. The pulse width modulator is configured to modulate a power stage. The error integrator is configured to control the pulse width modulator. The open drain driver is coupled to the integrator enable circuit. The integrator enable circuit is coupled to the pulse width modulator, the error integrator, the open drain driver, and the integrator enable terminal. The integrator enable circuit is configured to activate the open drain driver responsive to generation of a power stage control pulse by the pulse width modulator, and activate the error integrator responsive to a logic low signal at the integrator enable terminal.

What is claimed is: 
     
       1. A multiphase controller, comprising:
 an integrator enable terminal; 
 a pulse width modulator; 
 an error integrator coupled to the pulse width modulator, and including:
 an enable input coupled to the integrator enable terminal; 
 
 an open drain driver including:
 a current terminal coupled to the integrator enable terminal; and 
 a control terminal; and 
 
 an integrator enable circuit including:
 a first input coupled to the pulse width modulator; 
 a second input coupled to the integrator enable terminal; 
 a first output coupled to the enable input of the error integrator; and 
 a second output coupled to the control terminal of the open drain driver. 
 
 
     
     
       2. The multiphase controller of  claim 1 , wherein:
 the open drain driver is a first open drain driver; and 
 the multiphase controller further includes:
 a controller startup terminal; 
 a second open drain driver including:
 a current terminal coupled to the controller startup terminal; and 
 a control terminal; and 
 
 a controller enable circuit coupled to the control terminal of the second open drain driver. 
 
 
     
     
       3. The multiphase controller of  claim 2 , wherein the controller startup terminal is adapted to be coupled to a temperature sense terminal of a power stage. 
     
     
       4. The multiphase controller of  claim 1 , wherein:
 the open drain driver is a first open drain driver; and 
 the multiphase controller further includes:
 a controller fault terminal; 
 a second open drain driver including:
 a current terminal coupled to the controller fault terminal; and 
 a control terminal; and 
 
 a fault circuit including an output coupled to the control terminal of the second open drain driver. 
 
 
     
     
       5. The multiphase controller of  claim 4 , wherein the controller fault terminal is adapted to be coupled to a temperature sense terminal of a power stage. 
     
     
       6. The multiphase controller of  claim 4 , further comprising:
 a comparator including:
 a first input coupled to the controller fault terminal; 
 a second input coupled to a voltage reference circuit; and 
 an output coupled to an input of the fault circuit. 
 
 
     
     
       7. The multiphase controller of  claim 4 , further comprising:
 an average current terminal; and 
 a third open drain driver, including:
 a current terminal coupled to the average current terminal; and 
 a control terminal; 
 
 wherein:
 the output of the fault circuit is a first output; and 
 
 the fault circuit includes a second output coupled to the control terminal of the third open drain driver. 
 
     
     
       8. The multiphase controller of  claim 7 , further comprising:
 a comparator including:
 a first input coupled to the average current terminal; 
 a second input coupled to a voltage reference circuit; and 
 an output coupled to an input of the fault circuit. 
 
 
     
     
       9. A multiphase controller, comprising:
 an integrator enable terminal adapted to be coupled to an integrator enable terminal of a different multiphase controller; 
 a pulse width modulator configured to modulate a power stage; 
 an error integrator configured to control the pulse width modulator; 
 an open drain driver coupled to the integrator enable terminal of the multiphase controller; and 
 an integrator enable circuit coupled to the pulse width modulator, the error integrator, the open drain driver, and the integrator enable terminal, and configured to:
 activate the open drain driver responsive to generation of a power stage control pulse by the pulse width modulator; and 
 activate the error integrator responsive to a logic low signal at the integrator enable terminal. 
 
 
     
     
       10. The multiphase controller of  claim 9 , wherein:
 the open drain driver is a first open drain driver; and 
 the multiphase controller further includes:
 a controller startup terminal adapted to be coupled to a controller startup terminal of the different multiphase controller; 
 a second open drain driver coupled to the controller startup terminal; and 
 a controller enable circuit coupled to the second open drain driver, and configured to:
 deactivate the second open drain driver responsive to the multiphase controller being ready for operation; and 
 activate the second open drain driver responsive to a start of initialization of the multiphase controller. 
 
 
 
     
     
       11. The multiphase controller of  claim 10 , wherein the controller startup terminal is adapted to be coupled to a temperature sense terminal of the power stage. 
     
     
       12. The multiphase controller of  claim 9 , wherein:
 the open drain driver is a first open drain driver; and 
 the multiphase controller further includes:
 a controller fault terminal adapted to be coupled to a controller fault terminal of the different multiphase controller; 
 a second open drain driver coupled to the controller fault terminal; and 
 a fault circuit coupled to the second open drain driver, and configured to:
 activate the second open drain driver responsive to detection of a fault in the multiphase controller. 
 
 
 
     
     
       13. The multiphase controller of  claim 12 , wherein the controller fault terminal is adapted to be coupled to a temperature sense terminal of the power stage. 
     
     
       14. The multiphase controller of  claim 12 , further comprising a comparator configured to compare a voltage at the controller fault terminal to a fault threshold voltage. 
     
     
       15. The multiphase controller of  claim 12 , further comprising:
 an average current terminal adapted to be coupled to the average current terminal of the different multiphase controller; and 
 a third open drain driver coupled to the average current terminal and the fault circuit; 
 wherein the fault circuit is configured to activate the third open drain driver responsive to detection of an overvoltage fault. 
 
     
     
       16. The multiphase controller of  claim 15 , further comprising a comparator coupled to the average current terminal and the fault circuit, and configured to compare a voltage at the average current terminal to an overvoltage fault threshold voltage. 
     
     
       17. A multiphase converter, comprising:
 a first multiphase controller including:
 an integrator enable terminal; and 
 a controller startup terminal; 
 
 a power stage including a temperature sense terminal coupled to the control startup terminal of the first multiphase controller; 
 a second multiphase controller including:
 a controller startup terminal coupled to the temperature sense terminal of the power stage; 
 an integrator enable terminal coupled to the integrator enable terminal of the first multiphase controller; 
 a pulse width modulator configured to modulate the power stage; 
 an error integrator configured to control the pulse width modulator; 
 an open drain driver coupled to the integrator enable terminal of the second multiphase controller; and 
 an integrator enable circuit coupled to the pulse width modulator, the error integrator, the open drain driver, and the integrator enable terminal of the second multiphase controller, and configured to:
 activate the open drain driver responsive to generation of a power stage control pulse by the pulse width modulator; and 
 activate the error integrator responsive to the first multiphase controller generating a logic low signal at the integrator enable terminal of the second multiphase controller. 
 
 
 
     
     
       18. The multiphase converter of  claim 17 , wherein:
 the open drain driver of the second multiphase controller is a first open drain driver; and 
 the second multiphase controller further includes:
 a second open drain driver coupled to the controller startup terminal of the second multiphase controller; and 
 a controller enable circuit coupled to the second open drain driver, and configured to:
 deactivate the second open drain driver responsive to the second multiphase controller being ready for operation; and 
 activate the second open drain driver responsive to a start of initialization of the second multiphase controller. 
 
 
 
     
     
       19. The multiphase converter of  claim 18 , wherein:
 the second multiphase controller includes:
 a third open drain driver coupled to the controller startup terminal; and 
 a fault circuit coupled to the third open drain driver, and configured to:
 activate the third open drain driver responsive to detection of a fault in the second multiphase controller. 
 
 
 
     
     
       20. The multiphase converter of  claim 19 , wherein:
 the first multiphase controller includes an average current terminal; and 
 the second multiphase controller includes:
 an average current terminal coupled to the average current terminal of the first multiphase controller; and 
 a fourth open drain driver coupled to the average current terminal of the second multiphase controller and the fault circuit; and 
 
 the fault circuit is configured to activate the fourth open drain driver responsive to detection of an overvoltage fault. 
 
     
     
       21. The multiphase converter of  claim 20 , wherein the second multiphase controller includes a comparator coupled to the average current terminal of the second multiphase controller and the fault circuit, and configured to compare a voltage at the average current terminal to an overvoltage fault threshold voltage. 
     
     
       22. The multiphase converter of  claim 17 , wherein:
 the second multiphase controller includes a comparator configured to compare a voltage at the controller startup terminal to a fault threshold voltage.